Methods Of Mathematical Modeling Research Articles

Rapid Detection of Soil Available Phosphorus using Capacitively Coupled Contactless Conductivity Detection

Background: In China, the traditional method for analyzing soil available phospho-rus is inadequate for large-scale soil assessment and nationwide soil formulation demands. To address this, we propose a rapid and reliable method for soil-available phosphorus detection. The setup includes an on-site rapid pre-treatment device, a non-contact conductivity detection device, and a capillary electrophoresis buffer solution system composed of glacial acetic acid and hydroxypropyl-β-cyclodextrin. Methods: The on-site rapid pre-treatment process includes fresh soil moisture content detec-tion (moisture rapid detector), weighing (handheld weighing meter), stirring (handheld rapid stirrer), and filtration (soil rapid filter) to obtain the liquid sample, and direct injection (capil-lary electrophoresis detector). The phosphate ion detection parameters include capillary size, separation voltage, injection parameters, and electric injection. We used Liaoning brown soil, Henan yellow tidal soil, Heilongjiang black soil, and Anhui tidal soil as standard samples. Additionally, we used mathematical modeling methods and machine learning algorithms to analyze and process research data. Results and Conclusion: Following calibration with standard samples, the experimental blind test samples demonstrated conformity with the national standard method, exhibiting a relative standard deviation of less than 3%. The proposed pre-treatment device and non-contact con-ductivity detector are powered by lithium-ion batteries, rendering them ideal for extended field operations. The non-contact conductivity detector obviates the need for direct contact with test samples, mitigating environmental pollution. Furthermore, the neural network model exhibited the highest level of goodness of fit in chemical data analysis.

МОДЕЛИРОВАНИЕ ПРОЦЕССОВ ОХЛАЖДЕНИЯ И ФОРМИРОВАНИЯ ТВЕРДОСТИ ЭКСТРУДАТА

The objective of the study is to reveal the patterns of cooling and hardening the extrudate in the technological line for obtaining textured flour. Objectives: to identify cause-and-effect relationships and determine the result and factor indicators of cooling and hardening of the extrudate; to develop theoretical and calculation schemes for determining the state of the system under study and to obtain a model representation of its result indicators. The methods of mathematical modeling, organization and planning of the experiment, the apparatus of descriptive statistics, correlation and regression analysis, the theory of random processes, Pearson, Student and Durbin-Watson statistical tests, as well as the methods of mathematical analysis implemented in the Statistics computer package of the Maple system were used. Theoretical and calculation schemes for determining the state of the studied system of "cooling and hardening of the extrudate" are proposed, and high-precision model representations are obtained for predicting the values of the result indicators and associated biophysical properties of the semi-finished product. Based on the analysis of existing and used in food systems extrusion technologies for processing plant raw materials into textured flour, the prospects for using the physical properties that determine the structure of the resulting wheat extrudate are determined. The theoretical problem of model representation of temperature and hardness of extrudate changing during cooling in a given technological time is substantiated. Such physical quantity as hardness of extrudate depending on humidity of initial raw material, temperature mode of processing and design features of cooler significantly influences content of protein, dietary fiber and other biotechnological characteristics of semi-finished product which can be used for prediction of transformation of food raw material into textured flour with high accuracy. The regularities of change in hardness and temperature of the extrudate during its cooling are investigated, and model representations are obtained for forecasting this technological process, which generalize the well-known empirical Newton's law to the objects of the system of "cooling and formation of hardness of the extrudate".

Algorithm for determining the operating parameters of an electrical network in the problem of optimal reconfiguration in real time

Relevance. The need to develop technical solutions to reduce electrical energy losses in medium-voltage distribution electrical networks of oil and gas fields. Aim. Development of an algorithm for determining the parameters of the operating mode of an electrical network, applicable in a system of optimal control of the network configuration in order to reduce the level of electricity losses in the network. Methods. Mathematical modeling methods and combinatorial optimization methods. The nodal voltage method and the Newton–Raphson method are used to calculate the network operating mode. The mode is corrected using a sensitivity matrix. Results and conclusions. The authors have developed an algorithm for determining the parameters of the electric network operating mode when determining its optimal configuration. Optimization of the optimal configuration is performed based on the criterion of minimum active power losses in lines, taking into account the limitations on the power reserve of the feeding transformer substations and the number of normal breaks on one line. The developed algorithm is based on solving nonlinear systems of equations of nodal voltages using the Newton–Raphson method, as well as on correcting the parameters of the previously calculated operating mode using the sensitivity matrix. The optimal network configuration is determined by solving the combinatorial optimization problem using the branch and bound method. The operation of the algorithm is illustrated by the example of a network section containing two overhead power lines with two power sources and three feeding transformer substations. Based on the results of the analysis of all possible network configurations determined by combinations of normal breaks, it is concluded that the use of the algorithm will reduce the level of active power losses by up to 23.8%, which will increase the efficiency of the electric grid complex.

РАЗРАБОТКА КУПАЖЕЙ РАСТИТЕЛЬНЫХ МАСЕЛ СБАЛАНСИРОВАННОГО ЖИРНОКИСЛОТНОГО СОСТАВА

The aim of the study is to develop mixtures of vegetable oils with a ratio of ɷ6:ɷ3 PUFA in the range of 5–10:1. Tasks: to study the quality indicators of vegetable oils; to investigate the fractional composition of PUFA; apply mathematical modeling methods in the development of blends of vegetable oils. The results of the development of blends of vegetable oils with a ratio of polyunsaturated fatty acids (PUFA) ɷ6:ɷ3 in the range of 5–10:1 are presented. Organoleptic (color, transparency, taste and smell), physico-chemical (peroxide and acid numbers, vitamin E content) indicators and fractional composition of PUFA refined deodorized oils – sunflower of the first grade (manufacturer OOO Tovarnoe hozyajstvo (limited liability company), Saratov Region), rapeseed of the highest grade (OOO Armaz (limited liability company), Novosibirsk), corn brand "P" (AO Efko (joint-stock company), Belgorod Region) and unrefined cold-pressed chia oil (OOO Sibirskaya kletchatka (limited liability company), Tomsk Region). The compliance of the quality indicators of traditional oils with the norms of the current GOSTs and TR CU 024/11, chia oils with the requirements of the Codex Alimentarius, has been established. Codex Stan 210-1999 and TR TS 024/11. Good compatibility of the studied oils in terms of organoleptic characteristics for blending was revealed. A relatively high content of ά-tocopherol was found in sunflower (667.16±14.22 mg/kg) and rapeseed (554.63±10.14 mg/kg) oils, and relatively low content in corn (78.07±2.24 mg/kg), the average level is in chia oil (343.96±9.03 mg/kg). In all oils, an imbalance of PUFAs was determined: with a predominance of the ɷ6 (linoleic-cis acid) fraction – in traditional oils, the ɷ3 (ά-linolenic acid) family – in chia oil. With the help of mathematical modeling methods, where the “maximum content of vitamin E” and “minimum price” were the accompanying criteria, 6 blends were developed with a certain ratio of sunflower refined deodorized oil of the first grade (93.37–96.70 %) and unrefined sunflower oil cold-pressed (6.63–3.30 %), characterized by a balanced composition of ɷ6 and ɷ3 PUFAs in accordance with the regulated norms MP 2.3.1.0253-21.

A software module to assess the metabolic potential of mutant strains of the bacterium Corynebacterium glutamicum

Technologies for the production of a range of compounds using microorganisms are becoming increas­ingly popular in industry. The creation of highly productive strains whose metabolism is aimed to the synthesis of a specific desired product is impossible without complex directed modifications of the genome using mathematical and computer modeling methods. One of the bacterial species actively used in biotechnological production is Co­rynebacterium glutamicum. There are already 5 whole-genome flux balance models for it, which can be used for me­tabolism research and optimization tasks. The paper presents fluxMicrobiotech, a software module developed at the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, which implements a se­ries of computational protocols designed for high-performance computer analysis of C. glutamicum whole-genome flux balance models. The tool is based on libraries from the opencobra community (https://opencobra.github.io) within the Python programming language (https://www.python.org), using the Pandas (https://pandas.pydata.org) and Escher (https://escher.readthedocs.io) libraries . It is configured to operate on a ‘file-in/file-out’ basis. The model, environmental conditions, and model constraints are specified as separate text table files, which allows one to pre­pare a series of files for each section, creating databases of available test scenarios for variations of the model. Or vice versa, allowing a single model to be tested under a series of different cultivation conditions. Post-processing tools for modeling data are set up, providing visualization of summary charts and metabolic maps.

Forecasting the Dynamics of Summer Phytoplankton Species based on Satellite Data Assimilation Methods

Introduction. Mathematical tools integrated with satellite data are typically employed as the primary means for studying aquatic ecosystems and forecasting changes in phytoplankton concentration in shallow water bodies during summer. This approach facilitates accurate monitoring, analysis, and modeling of the spatiotemporal dynamics of biogeochemical processes, considering the combined effects of various physicochemical, biological, and anthropogenic factors impacting the aquatic ecosystem. The authors have developed a mathematical model aligned with satellite data to predict the behavior of summer phytoplankton species in shallow water under accelerated temporal conditions. The model describes oxidative[1]reduction processes, sulfate reduction, and nutrient transformations (phytoplankton mineral nutrition), investigates hypoxia events caused by anthropogenic eutrophication, and forecasts changes in the oxygen and nutrient regimes of the water body.Materials and Methods. To simulate the population dynamics of summer phytoplankton species correlated with satellite data assimilation methods, an operational algorithm for restoring water quality parameters of the Azov Sea was developed based on the Levenberg-Marquardt multidimensional optimization method. The initial distribution of phytoplankton populations was obtained by applying the Local Binary Patterns (LBP) method to satellite images of the Taganrog Bay and was used as input data for the mathematical model.Results. Using integrated hydrodynamic and biological kinetics models combined with satellite data assimilation methods, a software suite was developed. This suite enables short- and medium-term forecasts of the ecological state of shallow water bodies based on diverse input data correlated with satellite information.Discussion and Conclusion. The conducted studies on aquatic systems revealed that improving the accuracy of initial data is one mechanism for enhancing the quality of biogeochemical process forecasting in marine ecosystems. It was established that using satellite data alongside mathematical modeling methods allows for studying the spatiotemporal distribution of pollutants of various origins, plankton populations in the studied water body, and assessing the nature and scale of natural or anthropogenic phenomena to prevent negative economic and social consequences.

From Chaos to Fractals: A Review of Mathematical Modeling of Population Dynamics

The dynamic changes in population size are a core issue in ecological research and are crucial for understanding ecosystem stability and biodiversity. Chaos theory and fractal theory offer new perspectives for exploring population dynamics. Through mathematical modeling and computational methods, the complexity and intrinsic patterns of population changes can be revealed. This paper reviews the application of chaos theory and fractal theory in the study of population dynamics. The research covers the role of chaos theory in revealing the nonlinear characteristics of population dynamics and sensitivity to initial conditions, as well as the ability of fractal theory to describe population spatial distribution patterns and scale effects. Special attention is given to the application of the fractal model (_p_ model) proposed by Su et al. in analyzing species abundance distributions (SAD) within communities, and the potential value of chaos and fractal theories in practical ecological conservation and management. This paper finds that chaos theory and fractal theory provide powerful analytical tools for studying population dynamics, helping to understand the complexity and unpredictability of population size changes. The application of these theories not only enhances the understanding of population spatial structure and distribution patterns but also provides a scientific basis for biodiversity conservation and ecosystem management. Future research may further deepen the application of these theories, develop new mathematical models and computational methods to better predict and manage population dynamics. Through interdisciplinary collaboration, these theories are expected to play a greater role in ecological conservation and resource management

Calculation algorithm for a multilayer thermal insulation system of a thermal energy storage device with a high-temperature working fluid

RELEVANCE. Managing the surplus and deficit of electric power generation, which contributes to the stabilization of the energy system and enhances its reliability, is a pressing issue. One of the solutions is the development and implementation of thermal energy storage systems within distributed energy systems. An important task in their development is creating an effective insulation system. THE PURPOSE. To develop an algorithm for the effective design of insulation systems for thermal energy storages with high-temperature working bodies. METHODS. The research is carried out using theoretical methods, including thermal engineering calculation of thermal insulation layers and thermal conductivity analysis. Mathematical modeling methods were used to determine the thickness of the thermal insulation system of a thermal energy storage device. RESULTS. The design of a thermal energy storage device has been developed. Based on the developed algorithm, it was determined that the thickness of the thermal insulation system should be 151 mm (the thickness of the first thermal insulation circuit is 135 mm, the thickness of the second thermal insulation layer made of mineral wool is 16 mm), ensuring minimal heat loss at a temperature of the heat accumulator equal to 2000 °C. It was revealed that the radiant heat flux prevails in the layers closest to graphite, accounting for about 70% of the total flux. CONCLUSION. The study confirmed the effectiveness of the proposed multi-layer insulation system for thermal energy storage. The developed algorithm allows for the calculation of insulation systems of thermal energy storage, taking into account various parameters and operating conditions.

Numerical modeling of microwave exposure on polymer composite materials in a quasi-coaxial working chamber

A method for numerical mathematical modeling of heating polymer composite materials (PCM) in a quasi-coaxial microwave chamber has been developed in the COMSOL Multiphysics software environment. This allows to obtain the optimal design of the working chamber in accordance with the dimensions and specified physical properties of the composite in order to realize the given parameters of microwave influence on PCM.It has been established that at a minimum power level of 250 W, a quasi-axial microwave chamber provides an effective process of microwave energy dissipation during the processing of PCM with a filler in the form of a thin layer or sphere.

ВИКОРИСТАННЯ ФІЛЬТРУ КАЛМАНА У ВЕКТОРНІЙ СИСТЕМІ ЕКСТРЕМАЛЬНОГО КЕРУВАННЯ АСИНХРОННОЮ МАШИНОЮ

In the article the reactive power of an asynchronous machine (AM) in a stable mode is obtained as a function of three vari-ables: the angular speed of rotation of the AM shaft, the module of the rotor flux coupling and the moment of static load on the shaft. The AM power factor decreases in electric drives (ED) of industrial mechanisms in which the load moment while maintaining its direction of action can take a static value less than the nominal value. Therefore, in order to ensure a high power factor of an asynchronous ED in long-term operating modes with a variable load, a vector AM control system was created, in which the magnitude of the rotor flux coupling is regulated by the reactive power channel as a function of the mo-ment of static load on the shaft. To identify the moment of loading, as well as the angular speed of the rotor and its flux cou-pling, a Kalman observer is synthesized, which allows creating a vector control system with simultaneous regulation of the speed and power factor of the AM without physical sensors of the reference vector of the rotor flux coupling and its angular speed of rotation. The significant dependence of the extreme values of the rotor flux coupling for reactive power on the torque on the AM shaft and insignificant dependence on the speed has been proved. Stability and high control quality are achieved by simultaneous use of relay control laws, invariant to coordinate and parametric perturbations, and the effectiveness of the Kalman filter algorithm for identifying variable states in the feedback loop. Thus, the article theoretically substantiates the idea of creating a sensorless relay-vector control system for an asynchronous ED with simultaneous speed regulation and optimization of AM energy indicators. The mathematical model is created as a program written in the Matlab programming language. The operability of the proposed asynchronous ED control system was confirmed by the method of mathematical modeling. References 12, figures 6.

Matematiksel Modellemeler ve Pyton Analizi İle Bediüzzaman’ın Beşinci Söz Eserinin Görselleştirilmesi ve İncelenmesi

In this study, metaphorical expressions in Bediuzzaman's Fifth Word were visualized and analyzed with mathematical modeling methods. The transience of human life, the importance of the concept of gratitude and the connection between the world and the hereafter were associated with concepts such as mathematical optimization, limits and functional analysis. In addition, these analyzes were evaluated within the framework of modern analysis approaches and the accuracy of the results was emphasized. Within the scope of teaching methodology, it was discussed how storytelling and visualization methods that would facilitate individuals' understanding of abstract concepts could be applied. In particular, the role of mathematical modeling in understanding conceptual relationships has been emphasized. Based on the work examined in the study, figures and graphics such as the Temporality of Worldly Life, the Ratio Between Gratitude and the Magnitude of Blessings, the Connection between the World and the Hereafter, the Change of Health and Spirituality Over Time, the Relationship Between Social Contribution and Responsibility, the Relationship Between Worship and Sinning, the Effect of Spiritual Life on Physical and Spiritual Life, Provision of Sustenance by Power and the Elderly, the Effect of Prayer on Material Life, the Fractal Spiral of the Fifth Word, and the Network Relationship of Concepts in the Fifth Word have been prepared and commented on. Finally, the results obtained from the entire study have been expressed and discussed. Keywords: Bedüzzaman Said Nursi, mathematical modeling, Islamic studies, Python analysis, visualization.

Algorithm performance study pulse suppression of auto-oscillation phenomena in the electromechanical system of the electric traction drive in braking mode electric traction drive system in braking mode by methods of simulation modeling

Research relevance. Modes accompanied by increased sliding of a wheel with negative viscous friction, characterized by reduction of friction force at growth of sliding speed, can arise at the movement of the vehicle. In these cases, a loss of stability may occur, resulting in the excitation of auto-oscillation phenomena in the electromechanical system (road-wheel-mechanical drive-electric motor). The emergence of this process sharply increases the dynamic load of the system, which can lead to its failure or breakdown. As a consequence, the development of suppression methods of auto-oscillation phenomena is considered to be an urgent task.Purpose of the research. Verification of operability and efficiency of the suppression method of auto oscillations in the electromechanical system of wheel drive during braking of the vehicle.Materials and Methods. With the help of Lyapunov’ function analysis for the electromechanical system of wheel drive the suppression method of auto oscillation phenomena is substantiated. The study of the algorithm performance has been carried out with the use of MATLAB Simulink program complex.Research results. The operability and efficiency of the algorithm is proved by methods of simulation mathematical modeling, which allows its further use in the development of traffic control systems. In case of braking of the vehicle equipped with antilock braking system with the function of suppression of auto oscillations on a slippery support base the reduction of amplitudes oscillation of angular velocities of wheels by 80% and braking moments by 96% is observed. When this vehicle is braked on a high adhesion base, the amplitudes are reduced by 98% in angular velocities and 81% in torques. In simulation modeling of vehicle braking dynamics on a support base with low adhesion properties it has also been shown that in these cases the evasive maneuver can be performed, which indicates on the increase in controllability and active safety of the vehicle.Conclusion. The practical value of the study lies in the possibility of using the developed algorithm for suppressing auto oscillations in practical application as part of vehicle control systems. The developed algorithm can be used on vehicles of different classes equipped with individual traction electric drive of driving wheels.

Modeling of the qualitative state of oilseeds from soybean seeds by multifactorial analysis of factor areas

The production of oil products in Ukraine is a leader not only in the European but also in the world market of food and processing industry products, therefore, the priority areas of scientific research in this field are the effective assessment of the quality of the oil obtained. Existing methods for assessing this product by organoleptic characteristics are subjective and do not allow the use of parameters that require more complex measurement technologies; which in general makes it impossible to conduct a comprehensive analysis of the quality of the studied product. The purpose of this study was to develop and implement a mathematical modeling method for numerical analysis of the quality of soybean oil product varieties. Qualitative assessment of the studied oil varieties was carried out using such indicators as the mass fraction of fat, peroxide, and acid number; content of free fatty acids, phosphatides, moisture, and impurities; it allowed to perform a numerical analysis using dimensionless complexes regarding the condition of the studied oil product varieties and compliance with regulatory indicators. When processing experimental data and calculating the developed quality criteria, programming methods, Excel, and COMPASS mathematical environments were used, which allowed the construction of geometric quality models and the necessary assessment criteria. According to the results of the research, it turned out that the characteristics of the studied varieties "OAS Avatar", "ES Mentor", "Sigalia", "ES Mentor" and "Gallek" do not meet the requirements for compliance with the quality thresholds by 160 - 220%, however, their current characteristics, which were selected for assessment, are within the average normative indicators. The proposed mathematical models can be implemented for practical application in assessing the condition of any complex object of research using an unlimited number of characteristics. At the same time, the main requirements for these parameters are their breadth of coverage of the physical, mechanical, and chemical-biological properties of the product and the ability to provide an objective and thorough assessment of its condition.

Performance Analysis of NOMA Systems over Rayleigh Fading Channels in 5G Communication

This paper aims to analyse the performance of Non-vertical Multiple Access (NOMA) systems operating in radio communication systems, especially under Rayleigh fading channels. While NOMA technology improves spectrum efficiency by allowing users to share the same time and frequency resource, Rayleigh fading channels represent multipath propagation effects commonly encountered in real radio environments. In this research, the effects of different user power levels and channel conditions on performance metrics such as system capacity, error rate (BER) and energy efficiency are investigated. Using mathematical modelling and simulation methods, the performance advantages and limitations of NOMA under Rayleigh fading conditions are evaluated. The findings show that NOMA systems offer significant advantages in terms of spectrum efficiency and user fair sharing in Rayleigh fading channels, but require careful design for error rate and energy consumption optimisation. This study provides an important reference for more effective implementation of NOMA technology in radio communication systems.

DYNAMIC MODEL OF THE BUDGET OF AN EDUCATIONAL INSTITUTION

For the study of complex socio-economic systems in a number of cases the method of mathematical modeling is the most acceptable. One of the most famous models in economics is the Keynes model. This model is most widely used in macroeconomic research to regulate the state budget. An important problem is to expand the scope of application of Keynes model by modifying it for budget management in other systems (educational organizations, family). The introduction of digitalization in the management of educational institutions necessitates new approaches to modeling the problem of calculating and optimizing the budget of an educational organization. The problem of developing a modified Keynes model for the university budget is new, important and relevant. The solution to this problem will improve the efficiency of financial management of educational institutions. Purpose: to develop a dynamic model for distributing the budget of a university based on the modified Keynesian model. Methodology: modeling, theory of solving differential equations. Results: a modified Keynes model has been developed, allowing for the calculation and optimization of the budget of educational organizations. Practical implications: the obtained results can be applied to calculate and optimize the budget of an educational institution, in the management of financial resources of organizations and enterprises.

Mineralogical indicators of Holocene climate in sediments of the high-mountain Lake Sagan-Nur (East Sayan Mountains)

We present the first results of study of bottom sediments taken from the high-mountain freshwater Lake Sagan-Nur of glacial origin which is located on the Oka plateau (East Sayan Mountains). Comprehensive investigations of the mineral composition of Lake Sagan-Nur sediments accumulated during the last ~8600 cal. years were carried out. The research methods include X-ray diffractometry (XRD), infrared spectroscopy, laser grain size analysis, SiO2bio determination, AMS and 210Pb dating. The mineral composition of the bottom sediments is dominated by layered silicates, quartz and plagioclase; and also, the X-ray amorphous component consisting of biogenic silica and organic matter is constantly present. The method of mathematical modeling of XRD profiles was used for correct identification of the layered silicates. It was found that the clay mineral assemblage was stable comprising muscovite, chlorite, illite, mixed-layer illite-smectite and chlorite-smectite, kaolinite. At the same time, the quantitative ratios of these minerals and their structural characteristics were modified significantly in response to paleoenvironmental changes in the region. This feature reveals the potential of a number of phyllosilicates (illite, mixed-layer minerals) as indicators of paleoclimate in sedimentary sections of freshwater basins. The study of sediment composition and, especially, the precision mineralogical-crystallochemical analysis of layered silicates allowed us to reconstruct the paleolandscapes and climatic conditions of sediment accumulation for different Holocene sub-stages.

ЭЛЕКТРОИНДУКЦИОННЫЙ МЕТОД РАЗМОРОЗКИ НАДЗЕМНЫХ ВОДОВОДОВ С ВНУТРЕННИМ ОБЛЕДЕНЕНИЕМ

The purpose of the work is to determine the thermal fields in the wall of a pipe of different diameters from surface heating and to find the capacities invested and changing over time. Subject: thermophysical processes in a steel unlimited plate study of the distribution of temperature fields in the wall of a pipe of different diameters, using Fourier equations. Materials and methods: the methods of mathematical modeling of thermophysical processes are based on. The method consists in using an upgraded mathematical model of the Fourier thermal conductivity equation, while, during the calculation and to simplify it, the steel pipe is mentally cut and represented as an unlimited plate. When plotting the temperature distribution over the thickness of the pipe, the Lira CAD PC 2022 software was used. Results: the method allows you to quickly determine the capacity invested and changing over time. Conclusions: the method of determining heat distribution based on the modernized Fourier method of thermal sources allows you to flexibly model and quickly solve practical problems of estimating the distribution of thermal fields in the wall of a large-diameter pipe under transverse strip sections of surface heating and cooling with specified embedded positive specific capacities.

Algorithm for Detecting Reference Points on a Digital Electrocardiogram in Real Time

Relevance. The use of digital electrocardiographs and cardiac monitors with built-in algorithms for automatic processing, analysis and interpretation of electrocardiograms allows the doctor to effectively diagnose cardiac arrhythmias. It is known that in order to provide emergency care to a patient, the duration of arrhythmia diagnostics should not exceed several tens of seconds, which requires the emergence of new algorithms for detecting informative features indicating arrhythmia, operating in real time. The need to introduce new and effective technologies for diagnosing cardiovascular diseases is also reflected in public health development programmes.Research goal. Development and quality indicators analysis of the algorithm for reference points detection on a digital electrocardiogram, bearing informative signs for the procedure of arteries diagnosis.The methods used. The study is based on an analysis of existing approaches to the problem of reference points detection on digital electrocardiogram, as well as conducting a test of the proposed algorithms by mathematical modelling methods. The quality indicators of the algorithms defined in accordance with the principles of signal detection theory and diagnostic testing, at the junction of which the task of electrocardiogram reference point detection is located. The proposed algorithm was tested on materials of MIT-BIH Arrhythmia Database, which is widely used for verification and validation of real-time digital electrocardiogram signal processing algorithms.The results. The study proposes an algorithm for detecting reference points on a digital electrocardiogram that carry informative features for the arrhythmia diagnostic procedure. The proposed algorithm is based on digital signal filtering using a decision rule based on a three-step two-threshold principle of pre-processed electrocardiogram signal values comparison on a sliding window. An experiment on the materials of the open verified MIT-BIH Arrhythmia DB showed that the quality of the proposed algorithm for detecting reference points is higher than that of the algorithms used in modern digital electrocardiographs and cardiac monitors. The proposed algorithm based on digital signal filtering and the three-step two-threshold decision rule have elements of scientific novelty.The significance. The results of this work can be used in the development of digital heart rate monitors, cardiac devices and for automatic processing, analysis and real-time computer-assisted digital electrocardiogram signal interpretation.

Promising areas of scientific and technological transformation of the world's largest economies

Subject. The article addresses indicators characterizing the level of scientific and technological development of the world's major economies as of 2023. Objectives. The purpose is to examine trends and promising areas of scientific and technological transformation of the world's largest economies within the framework of global relevant concepts. Methods. The study employs methods of descriptive statistics, correlation and regression analysis, with the construction of a dendrogram of distribution of countries into clusters by the Ward's method. The statistical databases of the World Bank for 2022–2023 served as an information base. Results. The paper presents an overview of popular areas of domestic and foreign research within the topic under consideration, determines the circle of the largest economies in the world by the largest volume of GDP at purchasing power parity, assesses the level of scientific and technological development of the world's largest economies, defines the key parameters of scientific and technological transformation, and classifies countries by level of development based on methods of economic and mathematical modeling, provides a developed conceptual model of global scientific and technological transformation. Conclusions. The findings are of interest to government-specific governance structures and can be integrated into programs for scientific and technological transformation of industry within the framework of global concepts, taking into account potential spillover effects expressed in the form of expanding opportunities for diversification and commercialization of domestic research and development.

АНАЛИЗ ПОДХОДОВ К МОДЕЛИРОВАНИЮ ВОЗНИКНОВЕНИЯ, РАЗВИТИЯ И ЛИКВИДАЦИИ ЧРЕЗВЫЧАЙНЫХ СИТУАЦИЙ НА ГИДРОТЕХНИЧЕСКИХ ОБЪЕКТАХ

Currently, an important problem, both for society and for the economy of the country as a whole, remains the problem of the safety of water bodies, especially dams and other hydraulic structures. To date, there are more than 29 thousand hydraulic structures in the Russian Federation. The destruction of such facilities is of both defense, economic and social significance for the country, as well as a potential danger to the health and life of the population, as well as the entire natural environment. About 100 million people live in the zone of possible impact of damaging factors. Based on this, we can conclude that there is a need to minimize the probability of such events. Recently, the use of new innovative methods of monitoring hydraulic structures, including mathematical methods, has been intensively developing. In this paper, an analysis of approaches to modeling the occurrence, development and elimination of emergencies at hydraulic engineering facilities is carried out. Methods of mathematical modeling and forecasting of the situation in case of emergency situations at hydraulic engineering facilities are considered. The technology of situational modeling of natural and man-made emergencies is considered. The features of using various calculation methods to assess the consequences and dynamics of hazardous situations at hydraulic structures are shown